Quique Sanchez Flores says the FA Cup is not the best for a club like Watford due to the number of wins needed to clinch the trophy.
Watford are set to play Newcastle United in the third round of the competition on Saturday in what will be Sanchez's first taste of the FA Cup.
The Spaniard has relative success in cup competitions, guiding Atletico Madrid to the final of the 2009-10 Copa del Rey.
Premier League and Championship clubs must win six games to lift the FA Cup, and the Watford manager says an extended run in the tournament may cost his side.
"The FA Cup is more historic than the Copa del Rey in Spain because that has only been running since 1978," he said.
"Everyone wants to go to Wembley. We are able to win any single match at this moment but the FA Cup is so long, not just three or four games, so it is not the best thing for us.
"I don't want to change the rules of the FA Cup, but our team has its limits so we need to manage the players.
"It is a big opportunity for other players in the squad - we can win any match but we may need different tools."